Serotonin (5-HT) exhibits diverse physiological activity mediated by at least four receptor classes, the most heterogeneous of which appears to be 5-HT.sub.1. A human gene which expresses a fifth 5-HT.sub.1 subtype, named 5-HT.sub.1F, was isolated by Kao and coworkers (Proc. Natl. Acad. Sci. USA, 90, 408-412 (1993)). This 5-HT.sub.1F receptor exhibits a pharmacological profile distinct from any serotonergic receptor yet described. While 5-HT.sub.1F agonists have been reported by Audia and Nissen (U.S. Pat. No. 5,521,196) and Audia (U.S. Pat. No. 5,521,197), antagonists of the 5-HT.sub.1F receptor, and their pharmacological activity, were heretofore unknown. This invention provides novel 5-HT.sub.1F antagonists which are useful for the treatment of anxiety disorders.